Versus populum (Latin for "towards the people") is the liturgical stance of a priest who, while celebrating Mass, faces the people from the other side of the altar. The opposite stance, that of a priest facing in the same direction as the people, is today called ad orientem (literally, "towards the east" − even if the priest is really facing in some other direction) or ad apsidem ("towards the apse" − even if the altar is unrelated to the apse of the church or even if the church or chapel has no apse).
In the early history of Christianity it was considered the norm to pray facing the geographical east. From the middle of the 17th century, almost all new Roman Rite altars were built against a wall or backed by a reredos, with a tabernacle placed on the main altar or inserted into the reredos. This meant that the priest turned to the people, putting his back to the altar, for a few short moments at Mass. However, the Tridentine Missal is not celebrated versus populum since the Ritus Servandus gives corresponding instructions for the priest when performing actions that require him to face the people. In the Ritus Servandus, the rubrics say "with his hands joined before his breast, and with his eyes downcast, he turns toward the people from left to right." This would otherwise not make sense in the context of versus populum since versus populum assumes that he is already facing the people.
It has been said that the reason the Pope always faced the people when celebrating Mass in St Peter's was that early Christians faced eastward when praying and, due to the difficult terrain, the basilica was built with its apse to the west. Some have attributed this orientation in other early Roman churches to the influence of Saint Peter's. However, the arrangement whereby the apse with the altar is at the west end of the church and the entrance on the east is found also in Roman churches contemporary with Saint Peter's (such as the original Basilica of Saint Paul Outside the Walls) that were under no such constraints of terrain, and the same arrangement remained the usual one until the sixth century. According to Klaus Gamber, in this early layout the people were situated not in the central nave but in the side aisles of the church and, while the priest faced both the altar and east throughout the Mass, the people faced the altar (from the sides) until the high point of the Mass, when they would turn to face east, the direction in which the priest was already facing. This view is strongly criticized on the grounds of the unlikelihood that, in churches where the altar was to the west, they would turn their backs on the altar (and the priest) at the celebration of the Eucharist.
It was in the 8th or 9th century that the position whereby the priest faced the apse, not the people, when celebrating Mass was adopted in Rome, under the influence of the Frankish Empire, where it had become general. However, in several churches in Rome, it was physically impossible, even before the twentieth-century liturgical reforms, for the priest to celebrate Mass facing away from the people, because of the presence, immediately in front of the altar, of the "confession" (Latin: confessio), an area sunk below floor level to enable people to come close to the tomb of the saint buried beneath the altar. The best-known such "confession" is that in St Peter's Basilica, but many other churches in Rome have the same architectural feature, including at least one, the present Basilica of Saint Paul Outside the Walls, which, although the original Constantinian basilica was arranged like St Peter's, is oriented since 386 in such a way that the priest faces west when celebrating Mass.
The earliest Christian churches were not built with any particular orientation in mind, but by the fifth century it became the rule in the Eastern Roman Empire to have the altar at the east end of the church, an arrangement that became normal but not universal in northern Europe. The old Roman custom of having the altar at the west end and the entrance at the east was sometimes followed as late as the 11th century even in areas under Frankish rule, as seen in Petershausen (Constance), Bamberg Cathedral, Augsburg Cathedral, Regensburg Cathedral, and Hildesheim Cathedral (all in present-day Germany). In the east also, the original Constantinian Church of the Holy Sepulchre in Jerusalem had its apse to the west until it was Byzantinized in 1048.
In the Roman Rite of the Catholic Church, the altar is "the center of thanksgiving that the Eucharist accomplishes" and the point around which the other rites are in some manner arrayed. Its importance was made evident by Romano Guardini (1885–1968), about whom Robert R. Kuehn wrote: "with him [Guardini] on the altar, the sacred table became the center of the universe" [...] The impact of the sacred action was all the more profound because Guardini celebrated the Mass versus populum – facing the people."
The present (2002) General Instruction of the Roman Missal says, in the official English translation: "The altar should be built separate from the wall, in such a way that it is possible to walk around it easily and that Mass can be celebrated at it facing the people, which is desirable wherever possible." Where practicable, the church altar should be built in such a way that the priest can easily walk around it and can celebrate Mass versus populum, but the text does not oblige the priest to avail of these possibilities.
In practice, after the Second Vatican Council, altars that obliged the priest to have his back to the people were generally moved away from the wall or reredos, or, where this was unsuitable, a new freestanding altar was built closer to the people. This, however, is not universal, and in some churches and chapels it is physically impossible for the priest to face the people throughout the Mass, as before 1970 some churches, especially in Rome, had altars at which it was physically impossible for the priest not to face the people throughout the Mass.
The present Roman Missal prescribes that the priest should face the people at six points of the Mass:
The Tridentine Roman Missal requires the priest to face the people, without looking at them, since he is directed to have his eyes cast down to the ground (Ritus servandus, V, 1; VII, 7; XII, 1), and, if he is at the same side of the altar as the people, to turn his back to the altar, eight times:
The Tridentine and the Vatican II editions of the Roman Missal expressly direct the priest to face the altar at exactly the same points. His position in relation to the altar and the people determines whether facing the altar means also facing the people.
In the second half of the 17th century, it became customary to place the tabernacle on the main altar of the church. When a priest celebrates Mass at such an altar with his back to the people, he sometimes necessarily turns his back directly to the Blessed Sacrament, as when he turns to the people at the Orate fratres. This seeming disrespect is absent when the priest stands on the side of the altar away from the people; but locating so large an object on the altar is arguably inconvenient for a celebration in which the priest faces the people. Accordingly, the revised Roman Missal states:
The Missal does, however, direct that the tabernacle be situated "in a part of the church that is truly noble, prominent, readily visible, beautifully decorated, and suitable for prayer" (GIRM 314).
Historically, priests in the Church of England and other churches of the Anglican Communion celebrated the Holy Eucharist standing at the north-end (i.e. the left side) of the communion table, according to the rubric in the Book of Common Prayer. This standard was challenged in the 19th century by the Oxford Movement, many of whose leaders preferred the ad orientem position, which was standard in the Roman Catholic tradition. At first, this was controversial, however, the rubric requiring that the priest stand at the north end of the table, facing liturgical South, was removed from the 1928 American Book of Common Prayer, which opened up the option to be widely practiced. Praying ad orientem then became common especially at the Gloria Patri, Gloria in Excelsis and Ecumenical creeds in that direction. However, over "the course of the last forty years or so, a great many of those altars have either been removed and pulled out away from the wall or replaced by the kind of freestanding table-like altar", in "response to the popular sentiment that the priest ought not turn his back to the people during the service; the perception was that this represented an insult to the laity and their centrality in worship. Thus developed today’s widespread practice in which the clergy stand behind the altar facing the people."
The United Methodist Book of Worship mandates that:
In our churches, the Communion table is to be placed in such a way that the presider is able to stand behind it, facing the people, and the people can visually if not physically gather around it. The table should be high enough so that the presider does not need to stoop to handle the bread and cup. Adaptations may be necessary to facilitate gracious leadership. While architectural integrity should be respected, it is important for churches to carefully adapt or renovate their worship spaces more fully to invite the people to participate in the Holy Meal. If altars are for all practical purposes immovable, then congregations should make provisions for creating a table suitable to the space so that the presiding minister may face the people and be closer to them.
In the Lutheran German Mass (Deutsche Messe), Martin Luther, the founder of that denomination, wrote that:
Here [in Wittenberg] we retain the vestments, altar, and candles until they are used up or we are pleased to make a change. But we do not oppose anyone who would do otherwise. In the true mass, however, of real Christians, the altar should not remain where it is, and the priest should always face the people as Christ doubtlessly did in the Last Supper.
In discussing the Divine Service, Lorraine S. Brugh and Gordon W. Lathrop write that "Many Lutherans, in concert with many other Christians, think that the time of which Luther spoke has indeed come, and that the pastor should preside at the table facting the people, i.e., versus populum. The assembly needs to have a sense that it is gathered around that table, sees and hears what happens there, has a promise of Christ clearly addressed to it, participates in the thanksgiving, and is made into a community through God's gift." Thus, in the Lutheran Church, many altars are now built to be freestanding. In churches where the former altar attached to the wall cannot be moved, it has often been converted to be used as a credence table, as a "significant new table is set up, closer to the people and standing free".
Cardinal Joseph Ratzinger (later Pope Benedict XVI) in his book the Spirit of the Liturgy criticised the use of versus populum as ahistorical and even harmful to the liturgy. He stated that versus populum "turns the community into a self-enclosed circle", where the presider becomes the real point of reference instead of God. He also maintained that praying toward the east (ad orientem) is a tradition that goes back to the beginning of Christianity and that is a "fundamental expression of the Christian synthesis of cosmos and history" and urged Catholics to gradually return to this tradition. On the other hand, he warned against quick and frequent changes to the liturgy, so he proposed a temporary solution - placing the cross in the middle of the altar, so the entire congregation "turns toward the Lord", who should be the real center of the Mass.
Edward Slattery, from 1993 to 2016 Bishop of the Roman Catholic Diocese of Tulsa, argued that the change towards versus populum has had a number of unforeseen and largely negative effects. First of all, he said, "it is a serious rupture with the Church's ancient tradition. Secondly, it can give the appearance that the priest and the people were engaged in a conversation about God, rather than the worship of God. Thirdly, it places an inordinate importance on the personality of the celebrant by placing him on a kind of liturgical stage".
On the other hand, the Jesuit theologian John Zupez, in an article in Emmanuel based on modern studies in scriptural exegesis, found that the New Testament word for sacrifice (hilasterion) refers to our expiation from sin, not propitiation impacting or appeasing God. This current translation, accepted in the Catholic lectionary, should "eliminate a strong argument for the priest at Mass facing toward God (ad orientem)" and "support the practice of the priest facing the people to elicit their active involvement." However, the Council of Trent had already authoritatively confirmed that "this sacrifice [of the Mass] is truly propitiatory."
In subsequent centuries the practice was clearly understood as rooted in Scripture and tradition and survived the Reformation in the Church of England. According to Dearmer: The ancient custom of turning to the East, or rather to the altar, for the Gloria Patri and the Gloria in Excelsis survived through the slovenly times, and is now common amongst us. (The choir also turned to the altar for the intonation of the Te Deum, and again for its last verse.) We get a glimpse of the custom after the last revision [i.e. 1662] from a letter which Archdeacon Heweston wrote in 1686 to the great Bishop Wilson (then at his ordination as deacon), telling him to ‘turn towards the East whenever the Gloria Patri and the Creeds are rehearsing’: of this and other customs he says, ‘which thousands of good people of our Church practice at this day.’ The practice here mentioned of turning to the East for the Creeds was introduced by the Laudian school, despite the direction in the Book of Common Prayer that ministers stand at the north-side of the table. It may well be doubted whether there is any reason for turning to the East to sing that ’Confession of our Christian Faith’ which is ‘commonly called the Creed of Saint Athanasius’… the proper use is to turn to the altar only for the Gloria Patri at its conclusion. [p. 198-199] It should be made clear that showing reverence to the altar or holy table, (historically Anglicans have used these terms interchangeably with varying emphasis over the centuries), when passing it, or in coming or going from the church etc. are indications of reverence for what occurs upon it, and not to be confused with turning to the East for the Creed, or when expressly addressing the Blessed Trinity in praise. This is admittedly slightly confusing, especially in churches which do not have an actual Eastward orientation. In such cases the direction of the church is presumed to be symbolically Eastward, and facing the direction of the principal altar is taken as East-facing, but Anglicans do not, as is sometimes supposed, face the altar for the Creed etc., rather it is the altar is aligned with our actual or symbolic orientation. The Hierurgia Anglicana records that the ancient practice of Eastward recitations were still retained at Manchester Cathedral in 1870, and Procter and Frere record that the custom at Salisbury, for recitation of the Nicene Creed only, "was for the choir to face the altar at the opening words, till they took up the singing, to turn to the altar again for the bowing at the Incarnatus, and again at the last clause to face the altar until the Offertory." [p. 391] J. Wickham Legg observed: "It will be noticed how persistent has been the custom in the Church of England of turning to the East at the Apostles’ Creed. Toward the end of the nineteenth century certain persons, hangers onto the High Church school, though unworthy of that honored name, discovered that the custom was only English, and they discontinued it in their persons." However Legg points out that it was recorded in seventeenth century France and it would seem to have been rather more widely observed than the Anglo-papalists he decries could have known. This would seem to be another instance of the liturgical conservatism of the English Church preserving a distinctive and once more universal expression of popular devotion otherwise abandoned. Another instance of orientation was the now much rarer custom of turning to the East for the Doxology at the conclusion of the recitation of each Psalm, particularly by those in choir. This was the custom at Probus in Cornwall in the early years of the nineteenth century, as it was in rural North Devon long before the influence of Puseyism: "all the singing time they used to face West, staring at the gallery, with its faded green curtains; and then; when the Gloria came, they all turned ‘right about’ and faced Eastward." [Legg, p. 180]
Many Episcopalians remember a time when the altars in most Episcopal churches were attached to the wall beyond the altar rail. The Celebrant at the Eucharist would turn to the altar and have his back – his back, never hers in those days – to the congregation during the Eucharistic Prayer and the consecration of the bread and wine. Over the course of the last forty years or so, a great many of those altars have either been removed and pulled out away from the wall or replaced by the kind of freestanding table-like altar we now use at St. Paul’s, Ivy. This was a response to the popular sentiment that the priest ought not turn his or her back to the people during the service; the perception was that this represented an insult to the laity and their centrality in worship. Thus developed today’s widespread practice in which the clergy stand behind the altar facing the people.
Some altar-tables have been built freestanding, with this kind of celebration in mind. But also some currently wall connected altars can be carefully moved to a new position, can be made to be freestanding. In yet other places, the old wall-altar cannot be moved but can be de-emphasized, become perhaps a place of flowers or a table for the vessels for holy communion (a "credence table"), while a significant new table is set up, closer to the oleo and standing free.